1. Materials Metals. Aluminum

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1 1. Materials Materials extraction in the world in 2013 was estimated at 84.4 billion (10 9 ) metric tons (45.8% industrial and construction materials, 26.8% biomass, 17.2% fossil fuels, and 10.2% metals, excluding unused portion), or 11.8 metric tons per capita per year [1]. In the United States during 2013, materials consumption, excluding fuels, was estimated at 3.78 billion (10 9 ) metric tons per year [2], corresponding to 11.9 metric tons per capita per year Metals Aluminum Aluminum production from bauxite via alumina is one of the most energy intensive processes in industry. According to a United Nations report based on 1979 data, the energy profile of aluminum is: consumption type MJ/kg Fraction Electricity Gas Other Mining % 6% 40% 54% Alumina % 12% 80% 7.5% Smelting % 85% 3% 12% Fabrication % 38% 51% 11% Total % Source: [3] Technologies have evolved (see [4] page 125), leading to greater energy efficiency. Compilation of multiple data sets for primary production (excluding the fabrication stage) yields an embodied energy in aluminum of 210 ± 10 MJ/kg [4, p. 471]. The carbon footprint for primary production is 12 kg of CO 2 /kg whereas the water usage varies from 495 to 1,490 L/kg [4, p. 471]. aluminum demands much less energy, only 26 MJ/kg for cast aluminum and 26.7 MJ/kg for wrought aluminum [5]. Its carbon footprint is 2.1 kg CO 2 /kg (in average). The estimated recycled fraction in 2012 ranged between 41% and 45% [4, p. 471]. 1

2 Copper and its alloys According to a United Nations report using 1975 data, the energy profile of copper is: consumption type MJ/kg fraction Electricity Gas Oil Other Mining % 42% 1% 35% 22% Concentrating ore % 73% 6% 1% 20% Smelting % 11% 48% 24% 17% Refining % 43% 15% 39% 2% Melting & Casting % Total % Source: [3] Technologies have evolved, leading other sources to provide lower numbers: Metal Embodied Carbon Footprint Water Usage Copper pure Recycled (40 to 45%) Copper alloys Recycled (40 to 45%) Brass Recycled (41 to 45%) Bronze Recycled (41 to 45%) Source: [4, page 477] and accompanying CES EduPack software Iron & Steel The amount of energy consumed in steel production varies widely based on the process used and on the mix of scrap metal with iron ore in the feed material. The Basic Oxygen Furnace (BOF) consumes 23.2 MJ/kg while the Electric Arc Furnace (EAF) consumes 9.3 MJ/kg [6]. The theoretical thermodynamic limit is 7.6 MJ/kg [3]. In the United States, the energy consumed for the production of steel is about 19 MJ/kg from iron ore [3] and 10 MJ/kg from scrap metal [3]. 2

3 Almost 40% of the world s steel production is made from scrap [7]. 1 kg of steel saves 1.1 kg of iron ore, 0.63 kg of coal, kg of limestone, kwh of electricity, L of oil, 10.9 thousand BTUs of energy, and 2.3 L of landfill [7]. Metal Embodied Carbon Footprint Water Usage Cast iron Recycled (40 to 45%) Casting energy Low carbon steel Recycled (40 to 44%) Low alloy steel Recycled (40 to 44%) Stainless steel Recycled (35 to 40%) Sources: [4, pages 463, 465, 467, 469] Lead Production of lead from ore (galena, PbS) requires 27 MJ/kg, 175 to 525 liters of water per kg and generates 2.0 kg of CO 2 per kg, while production of lead from recycled sources (mostly discarded automobile batteries) consumes 7.5 MJ/kg and generates 0.45 kg of CO 2 /kg. The single largest use of lead (70% of total production) is as electrodes in lead acid batteries [4, p. 479]. Magnesium Production of magnesium causes the following environmental impacts: Metal Embodied Carbon Footprint Water Usage Magnesium Recycled (37 to 41%) Magnesium alloys Recycled (36 to 41%) ,500 Source: [4, page 473] and accompanying CES EduPack software 3

4 Nickel Production of nickel causes the following environmental impacts: Metal Nickel chromium alloys Recycled (29 to 32%) Nickel based super alloys Recycled (22 to 26%) Source: [4, pages 483, 485] Embodied Carbon Water Footprint Usage Together with chromium and other elements, nickel is a component of stainless steel. Specialty and precious Metals Metal Embodied Carbon Footprint Water Usage Gold 240, ,000 26, , ,000 Recycled (42%) Iridium 43,000 47,600 2, , ,000 Recycled (0.7%) 2,000 2, Palladium 149, ,000 8, , ,000 Recycled (3%) 5,140 5, Platinum 257, ,000 14, , ,000 Recycled (3%) 7,760 8, Rhodium 531, ,000 30, , ,000 Recycled (0.7%) 13,500 14,900 1,120 Silver 1,400 1, ,150 3,460 Recycled (66%) Titanium alloys Recycled (23%) ,410 Source: [4, pages 127, 474, 487, 488] and accompanying CES EduPack software 4

5 Zinc Production of zinc causes the following environmental impacts: Metal Zinc Recycled (21 to 24%) Zinc die casting alloys Recycled (21 to 25%) Source: [4, page 481] Embodied Carbon Water Footprint Usage Plastics and rubber Except for biodegradable plastics, plastics are made from so called feedstocks derived from crude oil refining and natural gas processing. The rule of thumb is that half the fossil fuel goes into the plastic itself while the remaining half is combusted to provide the energy during manufacture. Thus, it takes about 2 kg of fossil fuel to produce 1kg of plastics. Since petroleum holds in average 43 MJ/kg, it takes approximately 86 MJ to produce 1 kg of plastics, and, with about 3 hydrogen atoms for every carbon atom in the fuel consumed in production (molar mass of 15 grams per mole), the CO 2 emission (with molar mass of 44 grams per mole) is 44/15 = 2.9 kg of CO2 for every a kg of plastics produced. Note: The amount of 6kg of CO 2 emitted per kg of plastic mentioned by Time for Change [8] is inaccurate. Actual amounts vary with the type of plastics, as the table below indicates. Polymers and Elastomers Acronym 5 Embodied Greenhouse gas Emission Water Usage Acrylonitrile butadiene styrene ABS Epoxy Ethylene vinyl acetate EVA ,5 3.1 High density polyethylene HDPE Phenolics Polyamides (Nylons) PA Polycarbonate PC

6 Polychloroprene CR Polyester Polyethylene PE Polyethylene terephthalate (PET) PET Polyhydroxyalkanoate PHA Polylactide PLA Polypropylene PP Polystyrene PS Polyurethane PU/PUR Polyvinyl chloride PVC Rubber natural NR (15 20) x 10 3 Rubber butyl rubber BR Styrene Source: [4, Chapter 15] and accompanying CES EduPack software 1 kg of plastics saves kwh of electricity, L of oil, 98 thousand BTUs of energy, and m 3 of landfill [7] Paper and cardboard There can grow 16 to 20 mature trees on 1 acre (40 to 59 trees per hectare) [9]. A cord of wood is 8ft x 4 ft x 4ft = 128 ft 3 and, if air dried and consisting of hardwoods weighs about 2 short tons (1,800 kg), about 15 20% of which is still water. One cord of wood makes 1,000 to 2,000 lbs of paper, depending on the process [10]. The production of 1 metric ton of paper requires 17 trees, in average, with the following spread: 24 trees for 1 ton of uncoated virgin (non recycled) printing and office paper but only 12 trees for 1 ton of 100% virgin (non recycled) newsprint, trees for 1 ton of higher end magazine paper (for glossy magazines), and 7.68 trees for 1 ton of lower end magazine paper (most catalogs) [11]. The production of 1 metric ton of paper consumes 51,500 MJ of energy, 25 m 3 of water, 680 gallons (2.57 m 3 ) of oil and generates 1,150 kg of CO 2 [4, 11, 12]. A "pallet" of copier paper (20 lb. sheet weight) contains 40 cartons and weighs 1 metric ton. It contains 440 reams, whereas 1 ream of paper contains 500 sheets and weighs 5 lbs = 2.27 kg. Therefore [11], 6

7 1 carton (10 reams) of 100% virgin copier paper uses 0.6 trees; 1 tree makes reams of copy paper or 8,333 sheets; 1 ream (500 sheets) uses 6% of a tree; 1 ton of coated, higher end virgin magazine paper (used for high end magazines) uses trees; 1 ton of coated, lower end virgin magazine paper (used for newsmagazines and most catalogs) uses 7.68 trees. In the USA, paper and cardboard recovery reached 66.8% in Of this, 33.4% went to produce corrugated cardboard, 11.8% non corrugated cardboard (boxboard), 8.6% tissue, and 0.8% newsprint. Net exports accounted for 39.8%. Also, 36% of the fibers used to make new paper come from recycled sources [13] Chemicals In the United States, the chemical industry consumes an average of 6,935 BTUs per lb of product [14]. This energy intensity, however, depends widely on the nature of the chemical, as the table below illustrates. Because different production paths consume different amounts of energy, the energy used in the production of a chemical depends on its feedstock. Chemicals obtained from the cracking and distillation of petroleum or inorganic sources are called raw materials. Thus, the total energy consumed in the production of a chemical is the sum of the energy inputs for itself and all its predecessors (each with the corresponding mass ratio deduced from the stoichiometric ratio), starting from the raw material. Example: The energy consumed in producing 1 lb of Ethylene Glycol from Ethylene Oxide (with mass ratio 0.710:1) from Ethylene as raw material (with mass ratio 0.637:1) is: E = 2, x (1, x 8,107) = 6,923 BTU/lb. To such number may be added the energy necessary for the intermediate production of the required hydrogen and chlorine. Chemical Consumption BTU/lb unless otherwise noted 7 When made from Mass ratio Acetic Acid (vinegar) 2,552 [15] Acetone 7,850 Acrylonitrile 956 Propylene 0.793:1 Ammonia 12,150 Ammonium 323 Ammonia 0.944:1 Ammonium Nitrate 341 Nitric Acid 0.787:1

8 Ammonium Phosphate 323 Ammonium Sulfate 4,000 Ammonia 0.258:1 Benzene 1,255 Petroleum Bisphenol A (BPA) 6 MJ/kg [16] 1,3 Butadiene 95 By product of ethylene Carbon Black 3,703MJ/ton [17] Chlorine 4,800 Sodium Chloride 1.648:1 Cumene (Isopropylbenzene) 696 Benzene 0.650:1 Cyclohexane 1,743 Benzene 0.928:1 Ethyl Benzene 1,404 Benzene 0.736:1 Ethylene 8,107 Petroleum Ethylene Dichloride 3,410 Ethylene 0.283:1 Ethylene Glycol 2,045 Ethylene Oxide 0.710:1 Ethylene Oxide 1,711 Ethylene 0.637:1 Formaldehyde 150 kwh/ton [17] Hydrochloric Acid 1.2MJ/kg [17] Hydrogen 1.8 GJ/ton Isopropyl Alcohol 4,693 Propylene 0.700:1 Methanol 38.4 GJ/ton Methyl Ter Butyl Ether (MTBE) 1,871 [18] Nitric Acid 267 Ammonia 0.270:1 Oxygen 1.8 GJ/ton [18] Phenol & Acetone together 7,850 Cumene 0.790:1 Phosphoric Acid 4,300 Sulfuric Acid 1.001:1 Polyethylene (PE) 1,178 Ethylene 1.000:1 Polypropylene 514 Propylene 1.000:1 Polystyrene 2,264 Styrene 1.000:1 Poly Vinyl Chloride (PVC) 1,246 Ethylene Dichloride Propylene 1,351 Petroleum Propylene Glycol 2,045 Propylene Oxide 0.763:1 Propylene Oxide 2,557 Propylene 0.725:1 Sodium Carbonate 3,393 Sodium Chloride negligible Sea Salt Sodium Hydroxide 3,765 Sodium Chloride 1.461:1 Sodium Silicate 5,344 MJ/ton [19] Sulfuric Acid 1,047 Styrene 16,891 Ethyl Benzene 1.019:1 Styrene Butadiene 1,3 Butadiene & 2,271 (synthetic rubber) Styrene 1.000:1 Terephthalic Acid 1,779 Xylene Titanium Dioxide 24.8 GJ/ton [19] Toluene 1,025 Petroleum Urea 843 Ammonia 0.567:1 Xylene 1,025 Source: [14] based on 1997 data, unless otherwise noted 8

9 1.5. Shaping of materials is not only spent in producing the material but also in shaping it into its desired form. shaping processes Material Shaping process use Carbon emission (MJ/kg) (kg of CO 2,eq /kg) Casting Rough, foil, rolling Metals 1 Extrusion, foil rolling Wire drawing Metal powder forming Vapor phase methods Polymers Extrusion Molding Ceramic Ceramic powder form Glasses Glass molding Compression molding Composites Spray /Lay up Filament winding Autoclave molding Source: [4, page 133] 1 For variations across metals, see [4]. Secondary processes Process type Variant use Carbon emission (MJ) (kg of CO 2,eq ) Heavy MJ kg Machining Finishing (light) 6 10 MJ kg (per kg Grinding MJ kg removed) Water jet, EDM, Laser MJ kg Welding Gas welding MJ kg (per m welded) Electric welding MJ kg Fasteners Fasteners, small MJ kg (per fastener) Fasteners, large MJ kg Adhesives Adhesives, cold 7 14 MJ kg (per m 2 ) Adhesives, heat curing MJ kg Painting MJ kg Painting (per m 2 Baked coating MJ kg ) Powder coatings MJ kg Plating (per m 2 ) Electroplating MJ kg Source: [4, page 135] 9

10 Polymer shaping Polymer use (MJ/kg) Molding CO 2 footprint (kg/kg) use (MJ/kg) Extrusion CO 2 footprint (kg/kg) Acrylonitrile Butadiene Styrene (ABS) Polyamides (Nylons, PA) Polypropylene(PP) Polyethylene (PE) Polycarbonate (PC) Polyethylene Terephthalate (PET) Polyvinylchloride (PVC) Polystyrene (PS) Polyhydroxyalkanoates (PHA, PHB) Polylactide (PLA) Epoxies Polyester Phenolics Rubber Natural Butyl Ethylene Vinyl Acetate (EVA) Polychloroprene (Neoprene, CR) Source: [4, pages ] 1.6. Miscellaneous materials production Greenhouse gas Material Water usage Embodied energy emission (L/kg) (MJ/kg) (kg CO 2 /kg) Anti freeze 76 Automotive Engine oil 60.2 Other fluids 52 Carbon fiber ,367 Alumina Ceramics Glass Pyrex glass Construction Brick Concrete

11 Sand 1.0 Stone Cotton ,400 8,200 Fiberglass (GFRP) Foams Rigid polymer Flexible polymer Straw bale Bamboo Woods Hardwood Plywood ,000 Softwood Wool ( ) x 10 5 Sources: [4 Chapter 15, 5] Sources [1] Sustainable Europe Research institute (SERI) in cooperation with Vienna University of Economics and Business < WU_MFA_Technical_report_2015.1_final.pdf>. See also Organization for Economic Cooperation and Development (OECD) < NMENT_key%20findings.pdf> [2] Center for Sustainable Systems, University of Michigan: U.S. Material Use <css.snre.umich.edu/css_doc/css05 18.pdf> For older data: U.S. Geological Survey, Fact Sheet <pubs.usgs.gov/fs/2009/3008/> [3] United Nations: Climate Change and Transnational Corporations Analysis and Trends. U. N. Centre on Transnational Corporations, Environment Series 2, 1992, ST/CTC/112, ISBN , Chapter 7 Production of Intensive Metals, 110 pages. [4] Ashby, M. F., 2013: Materials and the Environment Eco Informed Material Choice, 2 nd ed., Butterworth Heinemann, 616 pages. [5] Schubert, M., K. Saur, H. Florin, P. Eyerer, and H. Beddies: Life cycle analysis Getting the total picture on vehicle engineering alternatives, Automotive Engineering, March 1996, pp [6] Information Administration, U.S. Department of, 2011: Steel Industry Analysis Brief Consumption < [7] Bureau of International The Industry < [8] Time for Change: Plastic bags and plastic bottles CO2 emissions during their lifetime <timeforchange.org/plastic bags and plastic bottles CO2 emissions> [9] Wood Magazine: Let Your Trees Grow For Profit (undated article) < guide/lumber/let your trees grow for profit> 11

12 [10] Sierra Club: How much paper does one tree produce? < 4 july august/green life/how much paper does one tree produce> [11] Conservatree.org < [12] Thompson, C., 1992: Recycled Papers The Essential Guide, Cambridge, MA: MIT Press, 200 pages. Quoted by <conservatree.org/learn/enviroissues/treestats.shtml> [13] Paper Recycles <paperrecycles.org/statistics/paper paperboard recovery> and <paperrecycles.org/statistics/where recovered paper goes> [14] U.S. Department of, Office of Industrial Technologies: and Environmental Profile of the U.S. Chemical Industry, May <www1.eere.energy.gov/manufacturing/resources/chemicals/pdfs/profile_full.pdf> [15] Neelis, M., E. Worrell and E. Masanet: Efficiency Improvement and Cost Saving Opportunities for the Petrochemical Industry, Lawrence Berkeley National Laboratory, June < [16] Agrawal, R. and A. Suman: Production of Bisphenol A, Dept. Chemical Engineering, Jaypee University of Engineering and technology, Guna, India, < of Bisphenol A#scribd> [17] Hans Jӧrg, A., R. Hischier and M. Osses: Life Cycle Inventories of Chemicals, Swiss Center for Life Cycle Inventories, Zürich, December <db.ecoinvent.org/reports/08_chemicals.pdf> [18] Worrell, E., D. Phylipsen, D. Einstein and N. Martin: Use and Intensity of the U.S. Chemical Industry, University of California Berkeley, LNbL 44314, April < pdf> [19] Joint Research Centre, European Commission: Large Volume Inorganic Chemicals Solids and Others Industry, August <eippcb.jrc.ec.europa.eu/reference/bref/lvic s_bref_0907.pdf> 12